Detachable cover for a pull roll or collar



Q Unlted States Patent 12 Inventor RIJIOIIIS. Watson -[56]ReferencesCited y UNITED STATES PATENTS 211 Appl. No. 142,969

696,416 4/1902 Denegre.... 29/129x 221 Flled July 3,1968

986,712 3/1911 l-llpp 29/124 23;: magi" meme" Comm 2, 10,545 8/1939Burton 29/124 I H r 3,462,058 8/1969 Redman 226/191 W mm PrimaryExaminer-Allen N. Knowles DETACIIABLE COVER FOR A PULL ROLL OR COLLARAnorn'ey Walter G. Finch ABSTRACT: Pull rolls and pull collars havingmanually n chm. 8 m detachable split covers of resilient material, andprovided with US. 226/191, circumferential notches and under cuts forengaging and 29/129 retaining the covers, are disclosed. llt. PL B65h17/20 Both collar and cover are split, in a preferred embodiment Fieldof Search 226/ 190, of the invention, and the cover is extended radiallyonto a 191; 29/124, 125, I29, l32 uniform circumference of the collar.

Patented Nov. 3, 1970 3,537,632

/0 5 l2 I SHEET 2 /MATER/AL L Flaz PULL ROLL ASSEMBLY F/6 f I 47 3 F/G.4l6 1 I FIG. 7

FIG. 8 INVENTOR Raymond 5. W0 rson ATTORNEY longitudinally and which aregear driven in synchronism.

Commonly, one roll of the pair is made of metal and the opposed roll iscovered with a resilient material; or both rolls can be covered with aresilient material.

()ften, as for handling freshly printed paper, one roll is relieved inthe center so that the sheet material is touched only along the marginsofthe sheet. Such relief may be provided by attaching collars to a shaftin'lieu ofusing a relieved solid roll, in which case axial spacingbetween the collars may be adjusted as required to draw particularwidths of sheet material.

The radial spacing of pull rolls is usually made adjustable tocompensate for wear. l-loweventhe resilient covers eventually becomeworn beyond adjustment and must be replaced. It is also to be point outthat's heet fed machines using pull rolls will wear unevenly and nolonger feed properly, or can be damaged in a jam-up.

In the prior art, replacement of resilient covers typically requiresdisassembly of rollers from the process machinery with time required forreplacement and readjustment. Loss of production may be aggravated bydelay in securing replacement covers. Care is requiredin the disassemblyto avoid tool damage to the surfaces ofadjacent rollers. Where the coveris cemented in place, imperfect cementation can result in loss oftraction and stoppage of the process involved.

It is, therefore, an object of thepresent invention to provide improvedpull rollsandpull collars having resilient covers which are replaceablewithout disassembly'of any part other than the covers.

It is a further object of this invention to provide covers which arequickly, easily, and safely detachable by hand, without the use oftools. Y

Another object of this'invention is to provide pull rolls with coverswhich snap into place, and aresecure againstcircumundercut from a pointabove the pitch diameter to a point below the root dia'meter'of the gearand from shoulder 24 to ferential, radial, and axial displacement,without the use of adhesives.

Yet another object of this'inventionis to provide pull roll assemblieshaving split covers with smooth and uniformly resilient peripheralareas.

Still another object of this invention is to provide pull rollassemblies fashioned to standard machine component, designs, butadaptable to wide a variety of roller types and industrial applications.

To provide pull rolls with replacement covers which are quickly andeasily made as required, is yet another object of this invention.

The essence of this invention lies in provision of pull rolls, collars,and split collars, having circumferential notches and undercuts engagingand securing manually replaceable split covers of resilientmaterial.

Other objects and attendant advantages of this invention.

FIG. 4 is a face view in partial-section of a pull collar and acover-half;

FIG. 5 is a section ofa mold for making pull'collar covers; FIG. 6 is alongitudinal section of a pull roll and cover assembly;

FIG. 7 is an end view, of the FIG. 6 assembly; and

FIG. 8 is a section of a further cover configuration, according to thisinvention.

With reference now to FIG. 1 of the drawings, reference numeral l0depicts a pull collar and cover assembly affixed to a shaft S of part ofa typical pull-roll assembly. An identical pull collar is shown atright, in section.

Peripheries of the pull collars have resilient covers 14 which bear onametal roll M. The metal roll is geared at G to rotate with collar shaftS. An extended end of shaft S is rotationally driven by means (notshown).

In FIG. 2, there is shown a sheet material being pulled through the pullroll assembly by rotation of the pull collar 12 and cover assembly 10,and metal roll M, between which the sheet is caught. In FIGS. 3 and 4,the pull collar 12 is shown assembled with half ac'over 14.

Collar 12 is preferably made of cast iron, free machining brass, orother suitable metal. It is preferably split as at 13 and as shown inFIG. 4 into two equal parts and 12b, for ready assembly on and removalfrom, a shaft. The two parts are joined by screws 16, as shown in FIG.3, and the collar 12 is locked to a chosen shaft by a screw 18.

The following provisions are made for securing the cover 14 to thecollar 12. A notched ring or gear, having preferably an even number ofteeth 22, is formed in the exterior of the collar 12, as shown in FIGS.3 and 4.

No particular number of teeth is required. Uniform tooth size andspacing are preferred but are not essential. The teeth are preferablytapered in both sectional views, narrowing radially outwardly, tofacilitate assembly of the cover. This is made clearer later. The shapeof commercial timing belt teeth is well suited for the application.

The gear is defined axially by a shoulder 24 at the end of the collar,and a groove 26, leaving a circumferential land 28 on the exterior ofthe collar.

Cylindrical holes 30 and 32- are milled between teeth 22a and teeth 22bon opposite ends. of a diameter of the collar and at the split 13.

Size of the holes is made such that the teeth are substantially groove26.

Cover 14 is preferably made in two equal parts corresponding to those ofthe collar 12, the splits being on the same diameter as the splits inthecollar.

Preferred material for the cover is solid polyurethane, although rubberor other. flexible material may be used to suit specific applications.

FIG. 4 shows one-half of a cover 14 partly assembled on a collar 12 withthe free end of the cover shown partly in section. The cover 14 ispreferably made by casting polyurethane in a ring mold having the shapeof the collar, to secure a close, uniform fit to the teeth 22, the holes30 and 32, the shoulder 24, groove 26, and land 28; FIG. 5 shows such amold assembly 38. While the polyurethane is in the mold, the outer part40 of the mold may be removed and the outside diameter of thepolyurethane may be machine finished to the desired tolerance. FIG. 5will be discussed in more detail later. The polyurethane is removed fromthe mold by cutting on the previously mentioned split diameter, leavingsquare ends on the cover 14 as at 34.

When two such square ends are abutted and snapped into hole 30 or 32,the molded hemicylinders 36 securely lock the cover 14 to the collar 12at that point.

The cover 14 is readily separated from the collar 12 by manuallygrasping a cover half at one of the split ends and twisting it; removalotherwise is quite difficult. The cover 14 remains secure in normal use,retained radially by engagement with the holes 30 and 32 at the splitends, retained axially by engagement with .the shoulder 24 and groove26, and retained circumferentially by engagement with all the teeth 24,to prevent circumferential bunching of the cover 14 when it is pullingsheet material.

The portion of the cover 14 which extends over the land 28 is of uniformthickness and thus comprises a uniformly resilient peripheral area,providing smoother roller operation, as well as additional area forpulling sheet material.

It is not essential that the collar 12 be split, or that the split inthe collar coincide with the split in the cover 14, as shown in FIG. 4.However, an advantage of the provision ,of coincident splits in thecollar 12 and the cover 14 is that the pull collar assembly can beseparated into halves and bolted onto a shaft with the cover 14 in placeon the collar 12.

FIG. 5 shows a mold assembly 38 for casting covers 14 of solidpolyurethane. The outer ring 40 is made of rigid, machinable materialsuch as mild steel, and is closely fitted to the collar mold. An actualcollar 12, FlG. 3, may be used as part of the mold. Urethane in plasticform is poured into mold assembly 38 and hardened or cured therein usingtechniques well known in the art. The outer collar 40 is then removed,the outside diameter of the molded polyurethane cover 14 is machinefinished, if not within tolerance, the cover 14 is split by cutting, aspreviously described, and the cover 14 is removed, ready for use.

FIGS. 6 through 8 show several variations on the embodiment of the coverdescribed in reference to FIGS. 1-5, which are also applicable to thatembodiment.

In FIG. 6, cover 44 is mounted on a solid roll 46, shown in section. Nopart of the cover 44 extends over circumferential land 48, although suchextension can easily be fashioned to the desired length, as describedabove.

FIG. 7, an end view of HO. 6, illustrates another variation, a singlesplit in the cover, at 50. Since the cover material is chosen to beflexible in most applications, one split can be enough for removal ofthe cover 50.

FIG. 8, a section of a cover 52, shows a variation in proportion, thecover 52 being adapted to fit wide, shallow. teeth, as over the entirelength of a roll. The undercut in such case may extend any convenientdistance into the roll.

It is to be noted that, in addition to the above, metal male heads usedin conjunction with covered resilient heads, are widely used to score orcrease fibre or corrugated board. The

use of these detachable resilient covers for this application is part ofthis invention.

Obviously many modifications and variations of the present I the saidcircumference of. said pull roll in engagement with all said teeththereof and in engagement with the undercut adjacent the said split,said resilient cover having an extension onto said uniformcircumference.

2. in the combination as recited in claim I, wherein said undercutbetween said pair of teeth of said pull roll is a cylindrical aperturearranged substantially parallel to the axis of said pull roll.

3. in the combination as recited in claim 1, wherein the respective saiduniform circumference and said teeth of said pull roll are separated bya groove.

4. In the combination as recited in claim 1, wherein a said tooth ofsaid pair of teeth of said pull roll is radially tapered in section.

5. In the combination as recited in claim 1, wherein said pull roll hasa uniformly distributed plurality of teeth, including the said pair ofteeth, on the said circumference of said pull roll.

6. In the combination as recited in claim l, wherein said resilientcover is composed of solid polyurethane.

7. in the combination as recited in claim 1, wherein said pull rollcomprises a collar having a split passing through said undercut betweensaid pair of teeth a second pair of teeth on said collar with anundercut therebetween, and a second said split passing therethrough,with said resilient cover having plural splits respectively coincidentwith said splits in said collar.

8.'ln the combination as recited in claim 7, wherein said collar iscircular and the respective splits in said collar are at opposite endsof a diameter through said collar.

9. As an article of manufacture, a radially split resilient cover for apull roll having a pair of teeth on a circumference thereof and anundercut between said teeth and having a uniform circumference axiallyadjacent said pair of teeth, with said radially split resilient coverhaving a tooth thereon with a radial split therebetween for fittingaround said circumference of said pull roll in engagement with all saidteeth of said roll and in engagement with said undercut adjacent saidsplit of said cover, with said resilient cover having an extension ontosaid uniform circumference.

10. In an article of manufacture as recited in claim 9, whereinsaidradially split resilient cover is composed of solid polyurethane.

11. in combination,- a collar having a pair of teeth on a circumferencethereof and an undercut between the teeth, and a radially splitresilient cover fitted around the said circumference in engagement withall said teeth and in engagement with the undercut adjacent the saidsplit, said collar having a split passing through the said undercut,with a second pair of teeth in said collar with an undercut therebetweenand a second said split passing therethrough, said resilient coverhaving plural splits respectively coincident with said splits of saidcollar.

